To the Editor.—Rosenthal et al (Archives 1980;37:804-810) state that they identified "RDC + " (Research Diagnostic Criteria-positive) schizoaffective patients, including in this group patients who had one of the Schneiderian first-rank symptoms in conjunction with a major affective syndrome. However, inspection of theFrequency of Schneiderian First-Rank Symptoms in Bipolar I Affective Disorder Mania, Depression, No. of No. of Symptom Cases Cases Audible thoughts 10 7 Voices arguing 2 0 Voices commenting 5 0 Thought insertion 6 1 Thought withdrawal 4 3 Thought broadcasting 14 1 Delusions of control or influence 5 1 Delusional percept 1 0 Total 47 13RDC criteria for schizoaffective disorder and the list of Schneiderian firstrank symptoms (listed in the article) reveals that not all of the Schneiderian first-rank symptoms are sufficient for an RDC diagnosis of schizoaffective disorder. In particular, the symptom of "audible thoughts" is not sufficient; this is of considerable importance since this